1. Field of the Invention
The field of invention relates to a solid oxide fuel cell (SOFC) process and system. More specifically, the field relates to using a SOFC process and system using a vaporous hydrocarbon for producing electricity and carbon dioxide suitable for enhanced oil recovery (EOR).
2. Description of the Related Art
For long-time producing oil fields, EOR using carbon dioxide is a routine operation. Carbon dioxide injection repressurizes the field and fosters chemical reactions in the hydrocarbon-bearing formation that encourages additional hydrocarbon production. Purified carbon dioxide—at least 95 mole percent purity—is useful for EOR because it minimizes the likeliness of unknown or undesirable reactions in the hydrocarbon-bearing formation.
Both crude oil and natural gas production and refining are power-intensive enterprises. Recovery of hydrocarbon materials usually occurs in remote locations, including off-shore and away from significant population centers, where power conveyance infrastructure does not exist, is uneconomical or is physically impracticable. In such cases, local power generation facilities are the only realistic option.
Environmental conditions affect smaller, local power production facilities. Day-to-day cooling water and air temperature variations can leave some parts of a power generation system operationally limited, for example, cooling capacity. The local hydrocarbon feed stock can have impurities or can change in composition due to variations in the seasons. In addition, every location has access to hydrocarbon feed stock that is slightly different in hydrocarbon, contaminant and inert composition, making a “universal” system more difficult to design.
Power generation facilities create three major products: electricity, steam and carbon dioxide off-gas. The electricity and steam (generated as part of the process of combusting fuel as well as heating and cooling electricity-generating processes) are useful in all aspects of hydrocarbon-production and refining operations. With stringent greenhouse gas monitoring and reporting requirements, carbon dioxide is not jettisoned into the air simply as a “waste”. Instead, it is desirable to capture and find uses for the carbon dioxide produced or to minimize the amount of carbon dioxide emitted.
A power generation system and process that handles not only variability in hydrocarbon feed, including having the capability to take less refined vaporous feeds; is operable to provide electrical power at remote locations; and has the means for capturing and refining the carbon dioxide for use instead of disposing it, is desirable.